This proposal requests support for the purchase of a Zeiss LSM 710 confocal microscope, which will be a shared resource crucial to the work of five Major User laboratories at NYU School of Medicine as well as a valuable resource to outside users in the wider NYU School of Medicine community. The projects of the Major User labs, which are funded predominantly by 6 NIH R01 grants, address both how cell types are specified during embryonic development and how these different types of cells are rearranged to form functional organs. These studies include (1) identifying mechanisms of heart differentiation and morphogenesis in zebrafish embryos (Yelon);(2) investigating patterning of the Drosophila eye and the role of global transcriptional control in cell fate decisions (Treisman);(3) determining how C. elegans early embryonic cells and epithelial cells polarize (Nance);(4) learning how germ-line stem cells in C. elegans differentiate and proliferate (Hubbard);and (5) deciphering how the zebrafish vasculature becomes patterned (Torres-Vazquez). Each project relies heavily on the use of fluorescence microscopy to visualize cell shapes and movements and to examine the subcellular localization of proteins;because the embryos or tissues imaged are relatively thick, confocal microscopy is required to remove out-of-plane fluorescence. Accessory lasers that enable use of photoactivatable proteins and simultaneous imaging of GFP and mCherry are requested to enable new and powerful types of live imaging experiments. The Major User PIs are a combination of senior and junior faculty with considerable confocal microscopy experience. Together with Dr. Alice Liang, head of the Image Core Facility, they will cooperate in supporting and operating the confocal microscope. Dr. Liang will also oversee training and use of the scope by outside investigators throughout NYU School of Medicine. PUBLIC HEALTH RELEVANCE: The microscope requested in this proposal will be crucial in advancing the research of NIH-funded projects ongoing at NYU School of Medicine, and the requested accessory laser lines will enable new lines of investigation. Collectively the projects use model organisms to address fundamental questions in developmental biology, including how cells are patterned and organized to form organs. A basic understanding of these processes is critical to understanding human development and disease.